IMAGE FORMING DEVICE PROVIDED WITH ELECTRICITY SAVING FUNCTION

PURPOSE:To enable control based on power consumption and further, to prevent a fixing temperature from being unstable by an outside air temperature by providing a means changing a set temperature so as to make the detected power consumption almost coincident with reference power consumption. CONSTITUTION:A memory 14 stores the reference value of the power consumption of the image forming device in accordance with each mode in the image forming device, that is, each mode of a multimode for consecutively forming an image, a normal image forming mode, a mode using an original feeder, a standby mode not forming the image, etc. Moreover, the reference temperature of a fixing device in each mode and the tolerance level of the reference temperature are stored. In the image forming device, when the mode is selected, these reference power consumption, reference temperature and tolerance level are read out. Then, the reference temp. is transmitted to a temperature control circuit 5 as Lane set temp.. The circuit 5 controls a fixing heater 3 so that the temp. of the fixing device detected by a thermistor 4 becomes the set temp.